Black sulfur dye.



UNITED STATES PATENT Trice.

RICHARD KIROHI-IOFF AND EMIL HAUSSMANN, OF BERLIN, GERMANY, ASSIGNORS TO THE ACTIEN-GESELLSCHAFT FUR ANILIN FABRIKA TION, OF SAME PLACE.

BLACK SULFUR DYE.

SPECIFICATION forming part of Letters Patent N 0. 635,169, dated October 17, 1899.

Application filed August 11, 1899. Serial No. 726,865. (No specimens.)

To all whom it may concern:

Be it known that we, RICHARD KIRCHHOFF and EMIL HAUSSMANN, of Berlin, in the Kingdom of Prussia, German Empire, have invented new and useful Improvements .in Black Dyes; and we do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to which it appertains to make and use the same.

It is Well known that by melting with sulfur and sulfids of alkali metals certain nitrooxy derivatives of diphenylamin there are obtained coloring-matters which directly produce on the fiber black tints without requiring a subsequent oxidation. A coloring-matter of this kind is brought upon the market under the name of immedial-black. (Oompare United States Letters Patents Nos.

610,541 and 625,717.) On the other hand, it has been shown that by melting meta-phenylenediamin or meta-toluylenediamin with sulfur and sulfids of alkali metals at a more elevated temperature (220 to 260) brown to black dyestuffs are obtained. (United States Letters Patents Nos. 561,277 and 594,105.) At a lower temperaturesay 140 to 160- the aforesaid meta-diamins, according to our observations, do not at all yield a dyestuff when melted with sulfur and sulfids. We have now discovered that an unexpectedreaction takes place if sulfur and sulfids of alkali metals are allowed to react on mixtures of equimolecular proportions of a meta-diamin and of a nitrooxy derivative of diphenylamin. When these substances are melted together at about 140 to 160, a coloring-matter is formed which dyes cotton directly a dark green black shade. The shades obtained are very much different from those obtained with immedial-black, thelatter being more bluish black. As meta-phenylenediamin melted alone under the same conditions with sulfur and sulfid is not converted into a dyestuff, it might have been expected that the reaction would lead to the formation of a mixture of immedial-black and unchanged metaphenylenediamin. The different'properties of our new product and of immedial-black clearly prove, however, that under the conditions chosen the meta-diamin also enters into the reaction forming together with the nitrooxydiphenylamin derivativeanewcoloring-matter.

The following directions will explain in what manner we proceed in order to carry out our invention. Fortyeight parts, by weight, of sodium sulfid, seventeen parts of sulfur, and five parts of water are heated together, and to this mixture is added at to centigrade a mixture of ten parts of dinitrooxydiphenylamin and four parts of meta-phenylenediamin, (equimolecular proportions.) The formation of the coloring- Inatter commences at about centigrade. The temperature is slowly raised up to to Centigrade and maintained for about four to five hours. The dry melt is powdered and can be directly employed for dyeing. The product obtained inthis way forms in dry state a black powder which readily dissolves in water with a dull greenishblue color which on addition of caustic-soda lye turns slightly more bluish. The aqueous solution of the dye is precipitated when mineral acids or acetic acid is added, a brownishblack precipitate being formed. .By the illtroduction of a current of air or carbonic acid into the aqueous solution of the dye a darkblue precipitate is separated after some time. In concentrated sulfuric acid the dye dissolves slowly with dirty-green color, while in fuming sulfuric acid containing about twenty per cent. anhydride it dissolves with a bluish-black color.

The dye is practically insoluble in solvents such as alcohol, benzene, ether, nitrobenzene, inc.

-Our new dye produces directly on unmordanted cotton black shades.

Thefollowing alterations may be made in the above example without materially changing the character of the product obtained. Instead of directly introducing the diamins into the reaction we may equally well use the corresponding nitro derivativesthat is to say, meta-nitranilin, meta-nitrotoluidin, or meta dinitrobenzene and meta dinitroto luenc, these substances being converted into the amido products by the action of sullids during the melting process. Further, the quantities of sulfur and sodium sulfid in the above example may be varied within wide limits, and we do not confine ourseves to the figures given in the above example.

Having now described our invention and in what manner the same can be perf0rmed,what we claim as new is- The black dye which results from heating equimolecular proportions of dinitrooxydiphenylamin and meta-phenylenediamiu with sulfur and alkali sulfids, said dye being readily soluble in water containing a small portion of alkali sulfid with dull greenish-blue color, which on addition of caustic-soda lye turns slightly more bluish, the aqueous solu- RICHARD KIROHHOFF. EMIL I-IAUSSMANN.

Witnesses WALDEMAR I'IAUPT, WILLIAM MAYNER. 

